A high-pressure pump has a plunger which reciprocates to pressurize fuel in a pressurizing chamber. JP-2003-113759A shows a high-pressure pump which has a valve body and a suction valve. The valve body and the suction valve are arranged in a fuel passage communicating with a pressurizing chamber. The suction valve is seated on or unseated from a valve seat provided to the valve body in order to adjust a fuel quantity introduced into the pressurizing chamber.
In this high-pressure pump, a fastening member is threaded into a housing and its axial fastening force is applied to the valve body through an engaging member so that the valve body is fixed in the housing. The axial fastening force of the fastening member is set a large value in order to avoid a loose of the fastening member. Thus, the engaging member between the fastening member and the valve body should have a mechanical strength against the axial fastening force. The engaging member has thickness enough to endure the axial fastening force.
Consequently, the size and weight of the high-pressure pump are increased and a manufacturing cost is also increased.
EP-1413756A1 shows a high-pressure pump which has an annular engagement groove on a fuel passage inner wall surface. An engaging member having C-shape is engaged with the annular engagement groove. The engaging member is also engaged with the valve body to prevent the valve body from moving opposite to the pressurizing chamber. The engaging member receives large pressure from the fuel in the pressurizing chamber at a surface contacting with the valve body. In order to reduce stress applied to the engaging member, the annular engagement groove should have great depth. When the C-shaped engaging member is brought into an engagement with the engagement groove, the engaging member should be deformed in such a manner that an outer diameter of the engaging member becomes smaller than an inner diameter of the annular engagement groove. If the engaging member is made from general material, it is likely that the engaging member is plastically deformed to loose a spring function. On the other hand, if the engaging member is made from material of which hardness is improved by heat-treating, it becomes difficult to deform the engaging member so as to engage the engaging member with the engagement groove.